Synchronizing system



p 1936. w. s. LEMMON SYNCHRONIZING SYSTEM Filed Aug. 9, 1933 3 Sheets-Sheet 1 IN VENT OR Walter Lemm0n. BY

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A TTORNE Y5 Sept. 1, 1936. w 5 LEMMQN 2,053,091

' I SYNCHRONIZING SYSTEM Filed Aug. 9, 1933 a Shets-Sheet 2 INVENTOR War/fer 5. Lemma/7.

A TTORNE YS Sept. 1,,1936. w. s. LEMMON SYNCHRONIZING SYSTEM Filed Aug. 9, 1953 3 Sheets- Sheet 5 INVENTOR Walker 5. Lemma/7.

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A TTQRNE Y5 operated at substantially the same speed, means Patented Sept. 2 i, 1936 UNI SYNCHRONIZING SYSTEM Walter S. Lemmon,

mesne New Yorlr, N. Y., assignor, by assignments, to International Business Machines Corporation, New York, N. Y., a corporation of New York Application August 9, 1933, Serial No. 684,362 ii (on. I'm-4i) This invention relates toccmmunication systems employing synchronous, in-phase operation of a transmitter and a receiver. It applies particularly to a system wherein the intelligence is conveyed by electrical impulses identified by their timing with reference to an arbitrary time scale. For such a system it is requisite that corresponding cycles of the sender and receiver begin and end simultaneously. For example, if the letter a is represented by an impulse transmitted 30f after the beginning of a sender cycle, the same. letter must be received by the receiver 30 afterthe beginning of a receiver cycle. If the sender and receiver are in phase, the letter 0" will be reproduced when the letter a" is sent, but if they are out of phase another letter will be indicated in the receiver when the letter a is sent.

It is an object of the present invention to provide in a timed signal telegraph system having a sending collector and a receiving distributor for sending a phase control impulse at a predetermined point in the cycle of the sending collector and means in the receiver responsive toreception of the control impulse in any position of the receiving distributor other than that representing phase correspondence, for applying a corrective step to the receiving distributor.

i It, is a further object of the present invention to provide means in the receiver for operating a signal to indicate when thereceiving distributor is running in phase with the trotting collector.

It is a further obiect of the invention to elimi-' nate from the phase control means a portion of the control circuit contact means which extends through the same are as the letter or character contacts of the receiver. It is a particular ob-.-. ject of the invention to achieve'this result automatically when phase correspondence has been secured.

Other objects and advantages will hereinafter app a In the drawing forming partof this specification, I g I Figure 1 is a diagrammaticview illustratingsending and receiving apparatus;

Figure 2 is a fragmentary, side elevation partly in section illustrating a portion of the receiver;

and v Figure 3 is a transverse, vertical section taken on the line 3-3 of Figure 2, looking in the direction of the arrows.

The sender comprises. a commutator ring I which includes a phase control contact 2' and a multiplicity of letter contacts 2. The phase control contact is connected through a Conductor 4 -to' a battery 5, thence through a conductor 6 to suitable transmiting or broadcasting means indicated by the rectangle I. The transmitting means i is conneced by a conductor 8 with the hub portion of a sending collector 9. The battery 5 is efifective to produce an impulse through the transmitting means I each time that the collector 5 arm 9 wipes across the contact 2. The collector arm 9 rotates at uniform speed and hence the control impulses are sent out at uniform time intervals. Between successive control impulses the collector arm wipes across'all of the letter contacts 3 in predetermined order, completing a circult through the transmitter las it touches each contact. The contacts 3 are adapted to be selectively charged by meansnot shown, and any such contact that is charged will cause an impulse to be sent out as a collector arm 9 wipes across it.

' .Such an impulse will obviously be timed with reference to the phase controlimpulse in accordance with the position of the particular letter contact 20 which is charged.

The sender may be used in line telegraphy or for radio. A radio antenna i0 is indicated.

In the receiver an antenna II is connected to an amplifier l2 and this amplifier is connected as through a conductor l 3 to a battery II. The battery i4 is in turn connected througha conductor i5 with the hub portion of a rotary distributor arm iii. The distributor arm i6 carries two brushes ii and it which are connected to. one another by a conductor IS. The conductor i5 isconnected to a solid collector ring 20 with which the prong ii is in continuous contact. The ring 20 is mounted upon a disc 2i which 24 and 25. The brush il wipes across the ring segment 22 and the contacts 23, 24 and 25 as it rotates. The brush it as it rotates wipesacross letter contacts 26 which are carried by a disc 21. The discs 2| and 21 are fast upon a hollow shaft 28 and may be manually adjusted with the shaft as desired. For this purpose, the shaft 28 has fast upon it a worm wheel 29 which meshes with-a worm 30 fast on the shaft 3i. This manual adjustment is ordinarily a fixed adjustment and is not disturbed in normal operation. Each letter contact 26 carried by the disc 21 corresponds in position with one of the letter contacts 3 of the commutator disc I of the sender.

The contact 24 corresponds in position with the control contact 2 of the sender while blank Spac are provided on both the discs i andthe disc. I

21 corresponding to the positions of contacts 231 and 25.

when the apparatus is first set into operation 65 no letter impulses are transmitted. If the conoperation is repeated in each cycle until the impulse comes through with the'brush l'l 'in engagement with contact 23. Here'the effect of the engagement is still the same and the arm I5 is stepped forward until the control impulse is 5 transmitted'to the contact 24. The sender and receiver are now in phase. When the control impulse is transmitted to the contact 24 no corrective step is required and none is applied, but instead a signal indicating lamp is energized to show the operator that the sender and receiver are operating in phase. Should the speeds of the sender and receiver be different, however, any

lagging of the receiver will simply cause the brush i! to engage contact 23 so that a corrective step is applied to 'restore the in-phase relationship. Should the receiver gain on the sender the brush II will transmit the control impulse to-the" contact 25 and this will produce a backward corrector back to the amplifier l2, and thence.

. through the conductor l3 to the battery I 4. The impulse transmitted through the winding of electromagnet A attracts the armature 35 of the elec- 30 tromagnet and causes a pawl arm 31 connected thereto to turn a ratchet 38 one step in a clockwise direction, as seen in Figure 3. The ratchet 33 is fast upona shaft 33 and this shaft in turn has a pinion fast upon it. The pinion 40 35 meshes with a gear 4| which is co-axial with the shaft 42 of arm l5, and which is fast with a differential housing 43. The gear 4i and the housing 43 are normally held against rotation by friction members 44 which bear against a stationary frame member 45. The friction members 44 are supported upon piungers 45 which are slidably mounted in the gear 4| and which are impelled outward'against the frame member 45 by compression springs 41. Pinions 43 are mounted on 5 radial studs 49 carried by the housing 43. The pinions 48 mesh with a pinion 50 which is faston the shaft 42 and with a pinion 5| which is fast on a shaft 52. The shaft 52 is driven from the motor 53. The effect of rotating the ratchet 35 a 50 single step is to turn the housing 43, which carries the pinion 43, through a small angle, and thus to advance the shaft 42 relative to the shaft 52. 5

when a power impulse is transmitted through 55 the contact 23 the effect is the same as that described for the transmission through the ring 22, the only difference being that the current-is transmitted directly from contact 23 to conductor 34 through a conductor 54. This also serves to energize the electromagnet 35 and to advance the shaft 42 relative to the shaft 52. 7

When the control impulse is transmitted to the contact 25 from the distributor l5 the current flows through a conductor 55, the winding 55 of a retarding electromagnet R, and thence through conductors 51 and 53 tothe conductor 35. The winding 55 thereupon attracts an armature 35a which acts through a pawl arm 31a to rotate a ratchet 33a. The ratchet 33a acts 7 through a shaft 33a. and a pinion 43a to rotate to an in-phase condition so that the control impulse is delivered to the contact 24.

'When the control impulse is delivered to the contact 24 the current passes through conductor 53,-thence through the winding 50 of a dash-pot relay whereby the switch 33 is controlled. The current passes thence through a conductor 3| and a luminous electrical discharge tube 52 which may be filled with-any suitable rarefied gas; such as neon, and thence through a conductor 53 to conductor 58. The luminous electrical discharge tube52 is caused to signal to the operator that the receiving distributor arm I5 is running in phase with the collector arm 3 of the sender. This signal is received so long as the in-phase operation is continued, not .being interrupted momentarily from time to time as a single control impulse is delivered through the contact 23 or the contact 25 because of the slow action of the relay. The tube has no filament subject to burning and is therefore a very dependable signal. The dashp'ot relay controls the switch 33 and in fact the switch 33 is the retarded armature element of the, relay. The switch 33 is pulled open by the en-*' ergization of the winding 60, and is held open by 25 reason of the fact that the control impulses come through so frequently that the slowacting switch 33 does not have an opportunity to return and make contact. Thus the ring 22 is rendered inoperative as soon as in-phase operation is secured and it is maintained inoperative throughout the time when letter impulses are received. Since the letter impulses are not transmitted until phase correspondence has been secured, it is not possible for letter impulses to come through and pass through the ring 22 to interfere with the f maintenanceof the in-phas'e condition. a

I have described what I believe to be the best embodiments of my invention. Although the described embodiment is concerned with a telegraph system, it will be understood that the invention may be applied to many other uses, such as systems for the transmission of facsimiles or pictures in which it is important to have the electrical impulses which are transmitted, timed 45 in exact accordance with the movement of certain of the arrangements of the system. It will be understood, therefore, that I do not wish to be confined to the embodiments shown, but what I desire to cover by Letters'Patent is set forth in the appended claims. I

I claim: J v

1. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising a collector operating at uniform speed and a receiver comprising a distributor operating at substantially the same speed, means in the sender for transmitting a phase control impulse at a predetermined point in each cycle and means in the receiver responsive to reception of the control impulse in all positions of the distributor other than that representing phase correspondence to apply one or more adjusting steps to the receiving distributor for stepping the same into phase correspondence with the said collector.

2. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising-a collectoroperating at uniform speed and a receiver comprising a distributor operating 'atsubstantially the same speed, ineans in the sender for transmitting a phase'control impulse at a predetermined point in each cycle and means in the receiver automatically responsive tothe control impulses to adjust the receiving 'distribmeans'in the sender for transmitting a phaseutor step by step into phase with the sending 'means in the sender for transmitting a phase concollector.

3. In a system for conveyingintelligence by electrical impulses, in combination, a sender comprising a rotary collector operating at uniform speed and a receiver comprising a rotary distributor operating at substantially the same speed,

trolimpulse at a predetermined point in each cycle and means in the receiver comprising a rotary brush carried with the distributor, a ring segment'in contact with the brush through the" major portion of the travel thereof, and means in circuit with the brush and ring for applying an adjusting step to the distributor when an impulse is transmitted through the ring.

4. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising a collector operating at uniform speed and a receiver comprising a distributor operating at substantially the same speed, a ring segment in circuit with the distributor through a portion of each cycle of the distributor for transmitting control impulses before phase correspondence has \been secured and for transmitting signal impulses after phase correspondence is secured, means in he sender for transmitting a phase control impulse at a predetermined point in each cycle, means in the receiver responsive to the received impulses to adjust the phase 'of the distributor, and means for rendering the ring circuit inoperative when pha'se' correspondence is secured.

5. In a system for conveying intelligence by electrical impulses, in combination,'a sender comprising a rotary collector operating at uniform speed and a receiver comprising a rotary distributor operating at substantially the same speed, a transmitting element in circuit with the distributor through a portion of each cycle. of the distributor for transmitting control impulses before phase correspondence has been secured and for transmitting signal impulses after phase correspondence is secured, means in the sender for transmitting a phase control impulse at a predetermined point in each cycle, means in the receiver responsive to the received impulses to adjust the phase of the distributor, and means automatically rendering the transmitting element inoperative to aifect the phase adjusting means 'when phase correspondence is secured.

6. In a system for conveying intelligence byelectrlcal impulses, in combination, a sender comprising a rotary collector operating at uniform speed and a receiver comprising a rotary distributor operating at substantially the same speed, a transmitting element in circuit with the distributor through a portion of each cycle of the distributor for transmitting control impulses before phase correspondence has, been secured and for transmitting signal impulses after phase correspondence is secured, means in the sender for transmitting a phase control impulse at a pre- *determined point in each cycle, means in the receiver responsive to the received impulses to adjust the phase of the distributor, and a means comprising a control circuit and slow acting relay responsive thereto for automatically rendering the transmitting element inoperative to eifect adjustment when phase correspondence has been secured.

'1. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising a rotary collector operating at uniform speed and a receiver comprising a rotary distributor operating at substantiallythe same peed.

control impulse at a predetermined point in each ception of the control impulse in the position of the distributor representing phase correspondence, and made effective thereby to indicate that the distributor is in phase with the sending collector.

8. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising a rotary collector operating at uniform speedand a receiver comprising a rotary distributor operating at substantially the same speed, means in the sender for transmitting a phase control impulse at a predetermined point in each cycle, means in the receiver for automatically adjusting the distributor to phase correspondence and a signal circuit in parallel with the adjust- .ing means and energized by reception of the control impulse in proper phase correspondence to indicate that phase correspondence has been secured.

9. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising a rotary collector operating at uniform speed and a receiver comprising a rotary distributor operating at substantially the same speed, means in' the sender for transmitting a phase control impulse at a predetermined point in each cycle and means in the receiver responsive to reception of the control impulse in the position of the distributor representing phase correspondence to indicate that the distributor is in phase with the sending collector, comprising a luminous electrical dischar e tube. I

10. In a system for conveying intelligence by electrical impulses, in combination, a transmitter for sending out control and signal impulses in timed relation to one another,-a receiver for such impulses, said transmitter and receiver having members rotating in substantial synchronism with each other, and means whereby said control impulses are caused to apply adjusting steps of predetermined extent to the said rotating member of the receiver if said member is out of syntransmitter.

ll. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising a rotary collector operating at uniform speed and a receiver comprising a rotary distributor operating at substantially the same speed,

a transmitting element in circuit with the distrib- ,utor through a portion of each cycle of the dise tributor for transmitting control impulses before phase correspondence has been secured and for transmitting signal impulses after phase correspondence is secured, means in the sender for trol circuit responsive to in-phase reception of the control impulses including a relay, and retarding means acting on the relay to delay the re-establishment of the operativeness of the transmitting element to eflect adjustment for a period exceeding that of a cycle of the distributor when the distributor deviates from phase correspondence.

V WALTER S. LEMMON.

chronism with the corresponding member of the 

